Purification of sulfuric acid.



No. 846,288. PATENTED MAR. 5, 1907. V. G. DRIFPIELD & P. W. WRIGHT. PURIFICATION OF SULPURIG ACID.

APPLIOATION FILED MAILZI, 190.6.

WITNESSES M M ATTORNE YS 'UNITEI) STATES PATENT OFFICE,

V EH6 CHARLES DltlFFlELD AN D FREDERICK. WlLLI'AM WRIGHT, OF LIVER- POOL, .ENGLAND, ASSIGNORS TO THE lTED, OF LIVERPOOL, ENGLAND.

PumF oATioN oF ISULFURIC ACID'.

No. 846,288. Specification of Letters Patent.

Application filed March 21,1906. Serial No. 307.187

.. atentea march 5, 1907.

To (pl/l whom, it may (JON/06PM.

Be it known that we, .Vnno ()imaLits DRIF- IVIELD, a subject of the King of Great Britain and Ireland, works manager, and FREDERICK WrLLIAM WRIGHT, a subject of the lung of Great Britain and Ireland, chem-1st, both residing at James street, Liverpool, in the county of Lancaster, England, have invented certain new and useful improvements in the Purification of SulfuricAcid, of which the following is a specification.

, The object of this invention is to effect in a ready, economical, and satisfactory manner the purification of sulfuric acid from arsenic. This is effected according to this invention by the addition of hydrochloric acid or asuitable chlorid, such as sodium chlorid, to the sulfuric acid to be purified and blowing air through. We will presume that hydrochloric acid is to be used. The sulfuric acid may be hot or cold during treatment, since the process may besuccessfully carried out under a range of temperature varying from 15 cen-' ti-grade to 200. centigrade, the best results 150 centigrade.

' chloric acid ;.but we do not limit ourselves to this apparatus.

A A representtwo earthenware vessels into which the sulfuric acid is admitted by the pipe B, and in its passage through these vessels it meets the liquid hydrochloric acid,

which is admitted by the pipes C, air being simultaneously blown through the mixture of acids by the pipes D. ,l The dearsenicated UNITED ALKALI COMPANY LIM- sulfuric acid escapes by the pipe E, while the arsenious chlorid and residual hydrochloric acid escape by the pipes F; or the sulfuric acid can be treated in a seriesof receptacles through which it successively passes, the hydrochloric acid and air being added to the first of the series, or the air can be blown into the leading receptacle ofthe series and the hydrochloric acid be passed into the second receptacle, the sulfuric acid passing in the reverse direction. As aforesaid, a suitable chlorid, such as sodium ehlorid, can be used instead of hydrochloric acid. The foregoing presumes that the arsenic is in the arsenious state. If'it be present in the arsenicstate a reducing agent (such as sulfurous anhydrid, for example) is introduced.

The arsenious chlorid which is evolved can be treated in any suitable manner for the obcertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is 1. The process of purifying sulfuric acid from arsenic, consis ing in treating at a temperature preferably between 90 centigrade and 150 cen'tigrade, the sulfuric acid with an agent capable of transforming the arsenic 4 -present in the arsenious state into arsenious chlorid, andblowing air'through the mix-.

ture, substantially as described.

2. The process of purifying sulfuric acid from arsenic, consisting in treating at a tem- I 4. The process of purifying sulfuric acid specification in the presence of two subscribfrom arsenic, consisting in treating the suiing Witnesses. furic acid with sulfurous anhydrid, then treating at a temperature preferably between 5 90 centigrade and 150 eentigrade with hy-- I droehl'oric acid and blowing air through the Witnesses: mixture substantially as described. JAMES SHAW AscR FT,

In testimony whereof we have signed this A. V. JOHNSON.

VERO CHARLES DRIFFIELD. FREDERICK WILLIAM WRIGHT. 

